Method of making nuts.



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WILLIAM REUBEN BLAKE, OF TONAWANDA, NEW YORK, ASSIGNOR T BUFFALO BOLT COMPANY, OF BUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

Specification of Letters Patent.

METHOD OF MAKING NUTS.

Patented Sept.3,1l1l8.

- Application filed April 13, 1917. Serial No. 161,717.

' To all whom it may concern:

Be it known that I, WILLIAM R. BLAKE, a citizen of the United States, and resident of Tonawanda, in the'county of Erie and State of New York, have invented certain new and useful Improvements in Methods of Making Nuts, of which the following is a specification.

My present invention is a method which I have devised-for making into smaller hexagonal nuts, the slugs which are punched from the "centerof the blank in making nuts of largerrs'ize, and although the method is obviously'applicable to making nuts any desired size or outline, from blanks derived from any desired source, I will describe it: in connection with the use for which it was primarily intended.

The slugs referred to are necessarily of peculiar and irregular shape because of the method of their production and heretofore they have been scrapped because of the difii culty of successfully: utilizing'them in automatic machinery for the production of other articles. My method successfully solves the problem of using them as blanks for nuts .and results in great saving in the cost of raw material.

Ina general way, the method consists of three operations, the first of which consists in simultaneously thinning and spreading the slug or other blank until its thickness is about the same and its diameter somewhat greater than that of the nut to be produced, forming a conical centering recess in its upper surface and on its lower surface, the crown for the nut and a central shallow recess corresponding to the central perforafitting the crown on its by any suitable machine of any desired type.

The details of this method will be more evident from the following description in connection with the accompanying drawings, in which,

Figure 1 is a side elevation of the blank while Figs. 2, 3 and 4 are "ertical sections showing the configuration of the punches and dies in their relation to the successive shapes imparted to the blank by the successive operations.

The blank shown in Fig. 1 is a slug punched from a large nut. Its periphery 1 is circular and its bottom surface 2 is flat where it was-engaged by the punch and is surrounded by slight marginal fin 3 formed by 'the metal wi ed back upon the punch. The top 4 is slightly convex and is slightly greater in diameter due to a slight flowing of the metal at the time it was originally forced outward by the pressure of the punch.

In practice, it is found that the flat lower surface 2 is usually concentric with and at right angles to the axis of the slug and this geometrically true surface I utilize as the base for securing approximately symmetrical and direct action of the punch upon the blank in the first operation.

In the first operation the slug is placed upon a die 5 having a level central surface 6. and a surrounding annular depression 7 having the shape desired for the crown of the nut to be produced. The depth of this depreshas cooperating therewith a vertically movable die 8. lts operating surface is a plane 9 at right angles to the direction of its movement and has a central conical projection 10 for engaging the top of the slug or other blank and forcing therein a conical centering depression operating to hold the slug in position and prevent unsymmetrical flow of the metal during the subsequent thinning and spreading operation.

The operation of the dies 5, 8 is regulated so as to flatten and spread the slug to about the dimensions indicated in Fig. 3.-

Fig. 3 shows the slug resulting from the operation above described in connection with Fig. 2, in position between the punching dies 11, 12, which are employed for the second operation. It will be noted that the blank now has a conical centering depression 10 on its upper surface and on its lower surface a crown 7 and the central recess (1'', The lower die 11 is shown with a central perforation 13 through which the center of the nut is to be punched, and surroumling said perforation is a depression 14 adapted to fit the crown previously formed in die The upper die 12 which is, more properly speaking, a punch, has a working face comprising a central conical projection 15 of the same size as the projection 10 on die 8. Surrounding said projection is an annular flat surface 16' somewhat like the surface 9 on die 8, but very much narrower, the diameter being the exact diameter of the perforation to be punched through the blank.

In operation, the centering cone 15 on die 12 first engages the similar depression 10 in the top of the blank, thus perfecting the centering and holding the blank while the punch is driven entirely through, thus forcing a slug of the metal out through the perforation 13 and leaving the central blank with a cylindrical central perforation, a

flat top, and a crown bottom, all as shown in Fig. 4. The punching operation is facilitated and rendered more accurate by reason of the above described recess 6 formedin the bottom of the blank by the first operation. This recess lessens the thickness of the metal to be pierced and moreover, being of somewhat greater diameter than the perforation 13, affords a certain amount of relief space into which surplus metal may flow during the punching operation.

The final operation consists in centering the crown over the hexagonal opening 15 in the trimming die 16, through which opening the nut forming portion of the blank is driven by the flat faced heXagonK-il punch 17.

I prefer to make the diameter of the hexagonal opening in the trimming die enough smaller than the blank so that the trimmed off outer portions of the blank which are left. behind will. include substantially all that part of the metal at the periphery which is likely to be overstrained, cracked or broken by the violence of the two preceding operations.

in certain cases, it may be desirable, particularly where the dies and punches are used in a ratchet feed dial press, to arrange the blanks in boxes formed in the dial plate as is common in such machines.

While I have described with great particularly all. of the features which I prefer to en'iploy in the practice of my method, it will be obvious that some of them are not essential, that it is not important which of the dies is uppermost or which is stationary and which movable; that cylindrical blanks other than slugs may be used and that the nuts produced need not be hexagonal.

I claim:

1. The method of making into smaller hexagonal nuts, the slugs punched from the center of the blank in making nuts of larger size. which method consists in supporting the slug upon the central, punchd'lattened surface thereof; then by progressive endwise pressure forming first a conical centering recess in the upper surface of the slug and then forcing its lower surface into a crown forming die while simultaneously thinning it to about the thickness, and spreading it to a greater diameter than the nut to be produced; then fitting the thus formed crown into a similar crown-formed recess surrounding a central perforation in a punching die; then first engaging said previously formed centering recess and by continued endwise pressure, perforating the center of the flattened slug; then centering the crown in the perforation of a trimming die of the size and form of the nut to be produced; and finally punching the thus flattened, crowned and pierced central portion of the slug, crown-first through said trimming die,

2. The method of cylindrically flattening and spreading punched slugs, which method consists in supporting said slug upon the central punclnfiattencd surface thereof with the marginal fin of said slug depending in annular recess in the support, pressing a central conical depression in the upper surface thereof and then continuing the pres sure until the slug ls thinned and spread to the desired extent.

3. The method of centering a metallic blank for a. die pressing operation and preserving said center duringa successive operation, which method consists in first supporting the blank upon a plane surface thereof, pressing a pointed circular recess in the opposite end thereof and a circular recess in the lower surface thereof concentric with the same vertical axis as said pointed recess during the first operation, and in a subsequent 1'Forging operation centering the blank by first engaging said concentric circular recesses with'cooperating similarly formed portions of the second set of forging implements and then completing such second forging opera tion by further continued movement of said implements in the same direction. I

'4. The method of perforating a blan l which consists in first forming-a conical rediameter than the perforation to be formed; i

then punching out saidperforation by first engaging said conical recess and then by continued pressure, forcing the excess metal partly into the annular margin of the above described recess and partly through-a suitable perforation in the supporting di'e.

Signed at North Tonawanda in the county of Niagara and, State of New York this 9th day of April A. D. 1917.

WILLXAM REUBEN BLAKE. 

